我有一个带有一个公共网络接口 (eth0) 的 Ubuntu 18.04 服务器。我正在尝试创建其他“虚拟”网络接口，这些接口也能够通过设置 NAT 规则访问互联网。
我使用以下命令创建了一个虚拟接口：
ip link add type veth
ifconfig veth0 192.168.1.1
下面是我的 ifconfig 的输出：
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255
ether f2:3c:92:1f:2a:62 txqueuelen 1000 (Ethernet)
RX packets 85664 bytes 111561237 (111.5 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 15392 bytes 2229468 (2.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
loop txqueuelen 1000 (Local Loopback)
RX packets 1385 bytes 213213 (213.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1385 bytes 213213 (213.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.1 netmask 255.255.255.0 broadcast 192.168.1.255
ether a6:e7:de:40:9a:28 txqueuelen 1000 (Ethernet)
RX packets 27 bytes 2082 (2.0 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1132 bytes 48520 (48.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
我已将“/proc/sys/net/ipv4/ip_forward”设置为 1：
$ cat /proc/sys/net/ipv4/ip_forward
1
我还尝试了许多 iptables MASQUERADE、FORWARD 和 NAT 规则，但无法从 veth0 访问 Internet。
当我从 veth0 接口 ping 192.168.1.1 时，一切正常：
$ ping -I veth0 192.168.1.1
PING 192.168.1.1 (192.168.1.1) from 192.168.1.1 veth0: 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.029 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.046 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.085 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=0.062 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=0.061 ms
--- 192.168.1.1 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4097ms
rtt min/avg/max/mdev = 0.029/0.056/0.085/0.020 ms
但是，如果我尝试从 veth0 ping eth0 接口 IP 地址，我没有得到任何响应：
$ ping -I veth0 10.0.0.1
PING 10.0.0.1 (10.0.0.1) from 192.168.1.1 veth0: 56(84) bytes of data.
--- 10.0.0.1 ping statistics ---
39 packets transmitted, 0 received, 100% packet loss, time 38900ms
下面是我的路由命令的输出：
Destination Gateway Genmask Flags Metric Ref Use Iface
default gw-li832.linode 0.0.0.0 UG 0 0 0 eth0
xx.xx.xx.xx 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 veth0
我似乎无法弄清楚我做错了什么，任何帮助将不胜感激。